Thermodynamic modeling of a solar energy based combined cycle with rock bed heat storage system

Solar Energy ◽  
2020 ◽  
Vol 200 ◽  
pp. 51-60 ◽  
Author(s):  
Merve Ozturk ◽  
Ibrahim Dincer ◽  
Nader Javani
Keyword(s):  
Solar Energy ◽  
Thermodynamic Modeling ◽  
Heat Storage ◽  
Storage System ◽  
Combined Cycle ◽  
Rock Bed

scholarly journals Experimental investigation on heat extraction from a rock bed heat storage system for high temperature applications

2016 ◽  
Vol 27 (2) ◽  
pp. 30 ◽  
Author(s):  
Denis Okello ◽  
Ole J Nydal ◽  
Karidewa Nyeinga ◽  
Eldad J K Banda
Keyword(s):  
Experimental Investigation ◽  
Solar Energy ◽  
Heat Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Cooking Time ◽  
Heat Extraction ◽  
Flow Conditions ◽  
Rock Bed ◽  
Air Speed

Solar energy is available in an intermittent way, and integrating an energy storage system with solar energy collection devices may promote uninterrupted supply of energy in the absence of the availability of solar energy. It has been shown that heat can be stored using rocks packed in a bed, but limited work has been reported on heat extraction from a charged rockbed. This paper reports on the heat extraction from a charged rock bed. Discharging tests were performed under different air flow conditions and initial bed temperatures. Without the blower, the discharging rate is very slow. The discharging rate can be increased, and the cooking time controlled by adjusting the air speed through the rock-bed system.

scholarly journals Dynamic model of a small scale concentrating solar cooker with rock bed heat storage

2016 ◽  
Vol 27 (1) ◽  
pp. 20 ◽  
Author(s):  
Karidewa Nyeinga ◽  
Ole J Nydal ◽  
Denis Okello ◽  
Eldad J.K.B. Banda
Keyword(s):  
Solar Energy ◽  
Dynamic Model ◽  
Heat Carrier ◽  
Heat Storage ◽  
Numerical Solutions ◽  
Storage System ◽  
Time Integration ◽  
Implicit Time ◽  
Small Scale ◽  
Rock Bed

This study presents a dynamic model for a concentrating solar energy collector with an integrated rock bed heat storage system. The model is based on numerical integration of a set of conservation equations for mass, momentum and energy of the heat carrier, the rock pebbles and the walls. The heat carrier is compressible air. Numerical solutions are implemented based on implicit time integration without iterations. Stability problems at large time steps do not occur but the accuracy is reduced. The model predicts pressure, velocity, density and temperatures of the fluid, rock bed and wall in time and along the bed. The model is validated with experimental results in a laboratory setting on temperature profiles during charging and discharging of rock bed heat storage. The intention is that the model shall serve as a computational tool for upscaling of air based concentrating solar energy systems with rock bed heat storage units.

Experimental Investigation on a Latent Heat Thermal Storage Unit for Solar Cooling Application

Green ◽  
2011 ◽  
Vol 1 (2) ◽  
Author(s):  
L. Chidambaram ◽  
A. S. Ramana ◽  
G. Kamaraj ◽  
R. Velraj
Keyword(s):  
Solar Energy ◽  
Latent Heat ◽  
Solar Collector ◽  
Heat Storage ◽  
Storage System ◽  
Thermal Storage ◽  
Environmental Crisis ◽  
Storage Unit ◽  
Latent Heat Storage ◽  
Solar Cooling

AbstractConventional cooling technologies that utilize harmful refrigerants consume more energy and cause peak loads leading to negative environmental impacts. As the world grapples with the energy and environmental crisis, there is an urgent need to develop and promote environmentally benign sustainable cooling technologies. Solar cooling is one such promising technology, given the fact that solar energy is the cheapest and most widely available renewable energy that matches the cooling load requirements. However thermal storage systems are essential to overcome the disadvantage of the intermittent nature of solar energy and variations in the cooling demand. The enhanced utilization of solar energy and other consequences of thermal storage integrated systems have gained the attention of researchers in recent years. The concept of combined sensible and latent heat storage system is successfully introduced in several applications and it has many advantages. This paper presents the performance of the solar collector system and the charging characteristics of a PCM based latent heat thermal storage unit, which is designed to provide continuous supply of heat for the operation of 1 kW vapor absorption refrigeration unit. Investigations on PCM integrated thermal storage system have revealed improvement in heat storage capacity, lower heat loss and an increased solar collector efficiency due to better thermal stratification.

Transient Heat Delivery and Storage Process in a Thermocline Heat Storage System

2009 ◽  
Author(s):  
Jon T. Van Lew ◽  
Peiwen Li ◽  
Cho Lik Chan ◽  
Wafaa Karaki ◽  
Jake Stephens
Keyword(s):  
Solar Energy ◽  
Power Systems ◽  
Heat Storage ◽  
Low Cost ◽  
Storage System ◽  
Filler Material ◽  
Working Fluid ◽  
Efficient Computation ◽  
Concentrated Solar Energy ◽  
Feasible Option

Parabolic trough power systems utilizing concentrated solar energy have proven their worth as a means for generating electricity. However, one major aspect preventing the technologies widespread acceptance is the deliverability of energy beyond a narrow window during peak hours of the sun. Thermal storage is a viable option to enhance the dispatchability of the solar energy and an economically feasible option is a thermocline storage system with a low-cost filler material. Utilization of thermocline storage facilities have been studied in the past and this paper hopes to expand upon that knowledge. The current study aimed to effectively model the heat transfer of a working fluid interacting with filler material. An effective numerical method and efficient computation schemes were developed and verified. A thermocline storage system was modeled under specific conditions and results of great significance to heat storage design and operation were obtained.

The Possibility of Using the Ground as a Seasonal Heat Storage: The Numerical Study

2004 ◽  
Author(s):  
Pawel Olszewski
Keyword(s):  
Solar Energy ◽  
Heat Storage ◽  
Numerical Study ◽  
Storage System ◽  
Heating System ◽  
Numerical Code ◽  
Space Heating ◽  
Solar Collectors ◽  
Seasonal Heat ◽  
The One

Humankind can effectively utilize only part of the solar energy reaching a surface of the Earth. It is due to the low density of the solar radiation and its unfavorable distribution. The majority of solar energy falls to the low latitude countries, where space-heating requirements are marginal. In these countries the solar heat is used for preparing water for washing or cleaning purposes, and this process works in one, or — maximum — a few daily cycles. In countries located at higher latitudes, where space heating is necessary in cold months, the current solar energy is insufficient to meet the space heating demand. The heat storage in deep layer of the ground is the one of possible way for solution of this problem. During the heating season, energy storage is discharged supplying the heat pomp cooperating with domestic heating system and during the summer months the storage can be charged by fluid heated in solar collectors. The main aim of presented research was analysis of using the ground layer as a heat storage system in the countries located in higher latitudes. The first variable taken into consideration was the output temperature of water leaving the solar collectors. The temperature distribution in the ground depends on the inlet water temperature, primary heated in the solar collectors, and forced into vertical boreholes. The temperature field in the ground was calculated using the duFort-Frankel finite-difference numerical method. A numerical code for 3D time dependent storage simulation has been created. The next step of analysis was calculation of waters’ temperature at the borehole output during cold months when the ground storage is discharged. This water works as a low-temperature reservoir of the heat pomp supplying the dwelling heating system. The solution of the problem is focused on an optimization of all parameters for the most efficient utilization of energy stored in the ground. The numerical genetic algorithms are scheduled to use to achieve this target.

Design and Application of a Seasonal Solar Soil Heat Storage System Applied in Greenhouse Heating

2014 ◽  
Vol 672-674 ◽  
pp. 21-25
Author(s):  
Liang Zhang ◽  
Peng Xu ◽  
Jia Chen Mao ◽  
Xu Tang
Keyword(s):  
Solar Energy ◽  
Energy Saving ◽  
Air Temperature ◽  
Indoor Air ◽  
Solar Collector ◽  
Heat Storage ◽  
Storage System ◽  
Control Subsystem ◽  
And Control ◽  
Design And Application

A seasonal solar soil heat storage (SSSHS) system applied in greenhouse heating has been designed and introduced. The system consists of solar collector subsystem, soil heat storage subsystem, greenhouse heating subsystem, hydronic subsystem and control subsystem. By applying soil heat storage, solar energy stored in the soil under the greenhouse can be transferred and utilized in winter to realize the utilization of cross-seasonal energy. TRNSYS is used to simulate the process and effect in the system of the solar energy collection and soil heat storage in Shanghai, and the simulation is calibrated to improve the precision of the TRNSYS model. When the indoor air temperature of the greenhouse is kept at 12°C throughout the year, the energy saving by using the SSSHS system in Shanghai can be 46.2kWh/(m2∙year).

scholarly journals 463 Experimental Study on Thermal Performance of Rock Bed Heat Storage System

2005 ◽  
Vol 2005.15 (0) ◽  
pp. 552-555
Author(s):  
Jun SUZUKI ◽  
Satoru NATSUSAKA ◽  
Himsar AMBARITA ◽  
Tosio YUTA ◽  
Mayumi SATOU ◽  
...  
Keyword(s):  
Experimental Study ◽  
Thermal Performance ◽  
Heat Storage ◽  
Storage System ◽  
Rock Bed

scholarly journals Simulation and Analysis of Influencing Factors of Solar Energy Inter-seasonal Soil Heat Storage

2021 ◽  
Vol 293 ◽  
pp. 03018
Author(s):  
Ping Lin ◽  
Xiangzhi Yao ◽  
Yunpeng Bai
Keyword(s):  
Solar Energy ◽  
Heat Storage ◽  
Storage System ◽  
Great Influence ◽  
Storage Period ◽  
Ground Temperature ◽  
Storage Effect ◽  
Practical Engineering ◽  
Seasonal Heat ◽  
Spacing Length

Taking an office building in Jinan as an example, the simulation model of solar inter-seasonal soil heat storage was established by TRNSYS software, and the variation law of ground temperature in the heat storage period was analyzed. From the perspective of ground temperature change, the influence of the spacing, length, number of drilling wells and area of solar collector on the heat storage effect was analyzed. The results showed that the soil temperature increased rapidly at the beginning of heat storage, and then the temperature rise rate gradually slowed down. The ground heat exchanger spacing, length, number of drilling and collector area will have a great influence on the solar energy seasonal heat storage effect. Therefore, in practical engineering applications, for the solar inter-seasonal soil heat storage system, the parameters of buried pipes, collectors and other components are recommended to be reasonably determined by simulation to obtain the optimal heat storage effect.

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